Liquid developer compositions

Abstract

A liquid developer comprised of thermoplastic resin particles, an optional charge director, and a charge additive or adjuvant comprised of a component of the formulas <IMAGE> or <IMAGE> wherein R1 is selected from the group consisting of hydrogen and alkyl, and n is 0 (zero), 1,2,3, or 4.

What is claimed is: 
     
       1. A liquid developer comprised of thermoplastic resin particles, an optional charge director, and a charge additive or adjuvant comprised of a component of the formulas ##STR5## wherein R 1  is selected from the group consisting of hydrogen and alkyl, and n is 0 (zero), 1,2,3, or 4. 
     
     
       2. A liquid developer comprised of a liquid component, thermoplastic resin, an ionic or zwitterionic charge director or directors soluble in a nonpolar liquid, and the charge additive, or hydrates thereof of claim 1. 
     
     
       3. A liquid developer comprised of (A) a liquid with a viscosity of from about 0.5 to about 20 centipoise and resistivity equal to or greater than 5×10 9  ; (B) thermoplastic resin particles with an average volume particle diameter of from about 0.1 to about 30 microns; (C) a nonpolar liquid soluble ionic or zwitterionic charge director compound; and (D) the charge additive of claim 1. 
     
     
       4. A developer in accordance with claim 1 wherein alkyl contains from 1 to about 25 carbon atoms. 
     
     
       5. A developer in accordance with claim 1 wherein R 1  is hydrogen, methyl, ethyl, propyl, or butyl. 
     
     
       6. A developer in accordance with claim 1 wherein R 1  is hydrogen, isopropyl, n-butyl, isobutyl, or tert-butyl. 
     
     
       7. A developer in accordance with claim 1 wherein the charge additive is a hydroxy aluminum complex of the formula as represented by ##STR6## 
     
     
       8. A developer in accordance with claim 1 wherein the charge enhancing additive is selected from the group consisting of hydroxy bis[3,5-di-tert-butyl salicylic] aluminate, hydroxy bis[3,5-di-tert-butyl salicylic] aluminate monohydrate, hydroxy bis[3,5-di-tert-butyl salicylic] aluminate dihydrate, hydroxy bis[3,5-di-tert-butyl salicylic] aluminate tri- or tetrahydrate and mixtures thereof. 
     
     
       9. A developer in accordance with claim 1 wherein the resin is a copolymer of ethylene and an α, β ethylenically unsaturated acid selected from the group consisting of acrylic acid and methacrylic acid; a copolymer of ethylene acrylic or methacrylic acid, alkylester of acrylic or methacrylic acid; or a copolymer of ethylene and methacrylic acid with a melt index at 190° C. of 500. 
     
     
       10. A developer in accordance with claim 1 containing a colorant, pigment, or dye. 
     
     
       11. A developer in accordance with claim 10 wherein the pigment is present in an amount of from about 5 to about 60 percent by weight based on the total weight of the developer solids. 
     
     
       12. A developer in accordance with claim 7 containing a pigment or dye. 
     
     
       13. A developer in accordance with claim 10 wherein the pigment is cyan, magenta, yellow or mixtures thereof. 
     
     
       14. A developer in accordance with claim 10 wherein the pigment is carbon black. 
     
     
       15. A developer in accordance with claim 1 wherein the charge additive is present in an amount of from about 0.1 to about 15 weight percent based on the weight of the developer solids, and there is enabled a negatively charged toner. 
     
     
       16. A developer in accordance with claim 3 wherein component (A) is present in an amount of from about 85 percent to about 99.9 percent by weight, based on the total weight of the liquid developer; the total weight of developer solids is from about 0.1 percent to about 15 percent by weight; and component (C) is present in an amount of from about 0.25 to about 1,500 milligrams/gram of developer solids. 
     
     
       17. A developer in accordance with claim 3 wherein component (D) is present in an amount of from about 0.1 to about 15 percent by weight based on the total weight of developer solids. 
     
     
       18. A developer in accordance with claim 3 further containing a charge adjuvant selected from the group consisting of polyhydroxy compounds which contain at least 2 hydroxy groups, amino alcohols, polybutylene succinimide and metallic soaps. 
     
     
       19. A developer in accordance with claim 1 wherein the liquid for said developer is an aliphatic hydrocarbon. 
     
     
       20. A developer in accordance with claim 6 wherein the liquid is an aliphatic hydrocarbon. 
     
     
       21. A developer in accordance with claim 19 wherein the aliphatic hydrocarbon is a mixture of branched hydrocarbons of from about 12 to about 16 carbon atoms, or a mixture of normal hydrocarbons of from about 10 to about 16 carbon atoms. 
     
     
       22. A developer in accordance with claim 20 wherein the aliphatic hydrocarbon is a mixture of branched hydrocarbons of from about 12 to about 16 carbon atoms. 
     
     
       23. An electrostatic developer in accordance with claim 3 wherein component (C) is an oil-soluble petroleum sulfonate, lecithin, or a quaternary ammonium block copolymer. 
     
     
       24. A developer in accordance with claim 1 wherein the resin is an alkylene polymer, a styrene polymer, an acrylate polymer, a polyester, or mixtures thereof. 
     
     
       25. An imaging method which comprises forming an electrostatic latent image followed by the development thereof with the liquid developer of claim 1.